Radar-
This deserves a separate mention. Because this is where the difference is at its max.
Su-30MKI has a N-011M BARS Radar
Transmitter peak power - 5kw
Transmitter average power - 1.2kw
Can Track- 15 Targets
Can Simultaneously Engage - 4 Targets
Max Detection for 5 sqm RCS - 140 km(Upgraded Radar with upgraded transmitter power, if any in service, its range is unknown.)

Both Su-35S and Su-30MKI aircraft are the super-maneuverability, with technological security RCS almost similar (Su-30MKI use the opto-electronic system of Europe, only to attack the land), I think we will have duel between Su-30MKI and the Su-35S (export version for China).

I think the Chinese Su-35, if any, will be used as the enemy assumes (referring to Su-30MKI), so the border if there is a conflict if the Su-30MKI can face thewith Su-35S (export version definitely will have reduced features, such as old AL-41F, no TVC2D/3D, no radar Irbis-E, no RAM tech, no OLS-35M) and the entire weapon old Russian (R-27/73/77) or new China's efficiency unverified (PL-8/9/10/12).